Criteria for interim decompression tables for caisson and tunnel workers.
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Contract 210-80-0110, 1980 Jan; :1-68
The development of interim decompression tables for tunneling and caisson workers is reviewed. Gas embolism and decompression sickness are defined. The former is caused by air trapped in the lungs, and the latter is caused by gas bubbles in the tissues and the resulting physiological reactions. Dysbaric osteonecrosis is noted as a form of decompression sickness. It results from the capillaries in the bone being blocked and the ensuing death of bone cells. The history of decompression sickness and empirically derived systematic decompression tables are discussed. The formal decompression code adopted in 1922 by the State of New York is cited. It embodied the principle of the split shift, in which workers were subjected to decompression twice daily under severe and traumatic conditions. The split shift was used until the introduction of the Washington State Tables. These were used until 1973, when severe aseptic necrosis was found in workers. The interim decompression tables are computer generated and are based on both positive and negative results for air and breathing mixtures under various pressure conditions; the system has been used to predict decompression adequacy for air and mixed gas exposures for divers and caisson workers and has been used to generate tables used in US Navy programs. Oxygen decompression tables and saturation decompression tables are also presented. The author concludes that the interim decompression tables should be required as a minimum for caisson or tunnel work until laboratory tested tables are available.
NIOSH-Contract; Health-hazards; Industrial-processes; Industrial-medicine; Occupational-medicine; Safety-practices; Health-standards; Biological-effects; Toxic-effects; Contract-210-80-0110
Final Contract Report
NTIS Accession No.
National Institute for Occupational Safety and Health
Sea Space Research Company